was at REI last night poking around for bells; saddles; clothing on sale etc. then the tri-suit caught my eye and tried on an XL. this was a short legged type with a tank top style upper.

https://www.rei.com/product/796655

I was surprised at how good I looked (though I did suck in my ab a bit). I mean I looked and felt very powerful and I can imagine that just wearing one would increase my speed by 1 mph! then taking it off exposing my chest with my arms back and rolling it down into a bit of an arm dip movement flexed my lats and chest and I was like ... holy cr*p!

anyone else experience an effect on performance by wearing a tri suit?

I noticed the bottoms weren't padded so one one just do the whole event in this garment? for me I can see swimming and riding in it but not running. I might be inclined to wear one under other clothing just for the sensation of this kind of full body compression garment.

how do tri suits and bibs differ?

I don't wear bibs because they are not for me. The trisuit is cool but a bit tight for my liking. I have used a trisuit twice and liked that I didn't have extra fabric flying around to drag me down. When I did the HIM last summer the trisuit was left at home and I wore my two year old swimsuit and lightly padded biking shorts. I was most comfortable in rags than the trisuit. In fact, I wore my Keen Commuter sandals instead of my tri shoes because it was so darn hot out there. I think one should find clothing and gear that works for him/her and roll with it. What is sold and others are sporting doesn't work for all.

Get a wetsuit. A full trisuit should be worth about 7-12 seconds per 100 yards. A shorty a bit less.
Do the math; that's 5-8 minutes in an Ironman.
Even in a 1.5/40/10 it's worth 1.5-3 minutes.

I was reading about slick suits which are legal, not considered a wet suit and can be used in waters above 80* with out penalty. There supposed to make you super slick in the water. Don't know about running or cycling in them, they probably suggest peeling them off like a wetsuit in t1.

I tied it on again and a full bib as well.

the XL trisuit fits but is much more snug than the same sized bib. I wish the trisuit came in an XXL but it doesn't - not the one I like in gunmetal grey at REI. I guess it would feel better/less tight if it were wet, huh?

my chest looks bigger in the blur trisuit; my chest looks massive in the bib; my everything chest; ABs; waist, etc looks awesome in gunmetal grey!

Where are you getting your information? Unless you are really really bad at swimming (like not making the cutoff bad) or the water is exceedingly cold (say, 50 degrees F) the difference is not more than 2-5 seconds per 100. I have tried some of the fastest suits (legskin for competitive swimming) in the world, fully tapered, everything not covered shaven, and I could only beat my best times by 3-5 seconds (depending on event) per 100.

As far as trisuits go, yes they do feel amazing. I tried on a 2XU one in a store and i just felt fast.

I got my tri suit last fall. The first thing I noticed was how difficult it was to use the bathroom when I had it on. Then I looked in the mirror and decided it was like a full body speedo, which isn't a flattering thing with my body.

But I'm wearing it to race not to make a fashion statement, lol.

Maybe I wasn't clear enough. I meant tri wetsuits. I get my data from over 30 years of swimming and over 20 years of coaching a( all but the highest levels.
Wetsuits provide exceptional buoyancy and increases in speed.

I got it and used it for a 44 mile ride to my GYM yesterday. It can probably be a tad larger but according to the charts I got the right size. maybe it will motivate me to diet more diligently. I'm wearing under my cycling pants for right now until warms up A LOT!

I stopped at a pizza shop and totally needed complete privacy to pee - so I see what you mean. Anyway, it makes me feel a bit more energized so maybe it will help overall performance. I'll try to do at least one swim in it!

For the extra furry among us I'd think it would reduce drag in the water.